I played the first one at a friend's earlier in the year and absolutely loved it. I swore off buying the sequel when it came out last month, opting to wait for the 360 version instead, but then I got a gift card a week later which was too much for a regular game, and too little for anything else, so I broke down and bought GHII.
I've five-starred all of Easy and Medium, have finished Hard, and am about halfway through Expert. Going back through and trying to five-star Hard and improve on Expert. Favorite songs to play are War Pigs, Jessica, the second half of Free Bird, and (of course) Sweet Child.